Fluid analyzer with variable light path

ABSTRACT

A turbidimeter or fluid analyzer having the length of the light path selectively variable whereby different ranges of turbidity, contamination or the like can be detected.

United States Patent 191 [4 1 May 14,1974

I FLUID ANALYZER ,wrrn VARIABLE;

LIGHT PATH [75] lnventer: James J. Shea, Dearborn Heights,

Mich.

[73] Assignee: Gam Rad Incorporated, Detroit,

' Mich. 221v Filed: Dec. 14,1972 21 [s im/54315093 52 us. Cl. 356/73, 356/103, 356/208,

[51] lnt.-Cl. ..G01n 21/00, GOln 1/10 ['58] Field of Search... 356/208, 72, 73', 103, 246; 250/218 [56] 0 References Cited UNITED-STATES PATENTS 2,690,695 10/1954 C6aes...=.;...; .l 356/246 3,234,846 Cropper et a] 356/208 3,526,462 9/1970 McCnrdy et al 356/246 3,614,243 10/197] Harvey 356/246 Primary Examiner-Ronald L. Wibert Assistant Examiner-V. P. McGraw Attorney, Agent, or Firm.loseph R. Papp [5 7'] ABSTRACT A turbidirneter or fluid an'alvzer having the length of the light path selectively variable whereby different ranges ofturbidity, contamination or thelike can be detected.

15 Claims, 5 Drawing: Figures FLUID ANALYZER WITH VARIABLE LIGI-ITPATH SUMMARY BACKGROUND OF THE INVENTION The present invention relates to turbidimeters or fluid analyzers and more particularly to turbidimeters or fluid analyzers of the type having apparatus for selectively varying the light path.

With the recent emphasis on pollution control the number and variation of applications for turbidimeters or fluid analyzers as fluidflow monitors has increased. In these various applications, however, the materials providing the turbid condition or contamination may be so different as to require a substantially different range of operation from one application to the next, e.g., the difference between an aqueous solution with fly ash particles and a caustic mud slurry. Rather than requiring a different device to accommodate each of the different types of conditions for various applications, it would be desirable to provide a single device capable of adjustment to accommodate these various conditions. In the present invention thisis accomplished by providing a device of the above described type with means for selectively varying the light path whereby these various conditions canbe accommodated.

Therefore, it is an object ofthe present invention to provide a new and improved turbidimeter or fluidanalyzer which is capable of use in various applications normally not within the range of a single device.

In a preferred form of the invention the device is-provided with means for selectively adjustingtlie length of the light path whereby different ranges of turbidity can be detected such that applications having substantial differences in turbidity characteristics can. be accommodated by a single device. Thus it is anotherobject of the present invention to provide a turbidimeter or fluid analyzer of the above described type having apparatus selectively adjustable for varying the length of the light path.

It is still another general object to provide for an-improved turbidimeter or fluid analyzer.

Other objects, features, and advantages of the present invention will become apparentfrom the subse quent description and the appended claims, taken in conjunction with the accompanying drawings, in which:

FIG I is a longitudinal sectional view taken generally along the lines 1-1 of FIG. 2ofa turbidimeter having apparatus for providing selective adjustment of the light path;

FIG. 2 is a sectional view of a portion of the turbidimeter of FIG. I and taken generally along the lines 22 of FIG. I;

FIG. 3 is an enlarged, sectional view of the sensor assembly of the turbidimeter of FIG. 1;

FIG. 4 is an end view ofthe apparatus of FIG. 3' taken in the direction of the arrow 4; and

FIG. 5 is a sectional view similar to FIG. 2 of another form of the invention.

1 Looking now to FIG. 1, a turbidimeter or fluid analyzer is generally shown and is indicated by the numeral and includes a flow tube assembly 12 and a'support housing 14. The tube assembly 12 includes a flow tube 16 which has flanges 18 at its opposite ends for connection in a flow line of an appropriate source of fluid to be analyzed or monitored.

The flow tube 16 has a necked down portion 24 intermediate its ends, which necked down portion is provided with a plurality of flats including flats 26 and 28 which facilitate the mounting of a light source assembly 30 and an adjustable sensor assembly 32. The light source assembly 30 includes a lamp 33 which can be energized by a suitable source of electricity and the output of which can be sensed and regulated via a regulator 34; regulator 34 can be of a type well known in the-art and hence the details thereof have been omitted for purposes of simplicity. The lamp 33 is connected to transmit its light through a lense assembly 36 and thence into the necked down portion 24 of the flow tube 16 via a window assembly 38. The window assembly 38 is connected to the flat portion 28 and includes a pair of spaced windows 39 and 40 with window 40 having its inner surface generally flush with the flat portion 28.

As can be seen in FIGS. 1 and 2, the flat portion 28 is directly opposite flat portion 26 and hence the sensor assembly 32, as shown, will indicate turbidity as a function of absorption of the light from source 30 by the particles carried by the fluid. Looking to FIGS. 1-3, the sensor assembly 32 includes a lense assembly 42 and a window assembly 44. The lense assembly 42 includes a lense 43 mounted in a stepped intermediate bore 45 in an annular housing 47. The window assembly 44 includesan elongated smaller diameter, tubular housing 49 which fits snugly within and is fixed in a counterbore 51 in housing 47. The outer end of housing 49 has a counterbore 53 in which are located a pair of spaced windows 55 and 57 separated by a space 59; an O-ring $83161 provides a seal between windows 55 and 57 and the counterbore 53; the end 83 of counterbore 53 is turned over to define a lip 63 to retain the windows 55, 57, spacer 59 and O-ring seal 61 within counterbore 53.

The flat 26 has an annular boss 65 extending axially outwardly which boss 65 defines a through bore 67 which is of a size to snugly, slidably receive the outer end of the tubular housing 49. The bore 67 terminates in a pair of stepped counterbores 69 and 71 and an O- ring seal 73 is adapted to be located within counterbore 6910 provide a seal between the boss 65 and housing 49. An annular locking collet 75 is snugly, slidably located on tube 49 and includes a shoulder 77 and inclined portion 79.

A lock nut 81 is slidably mounted on housing 49 and has a frusto conically shaped cavity 83 which is adapted to matably receive the inclined portion 79 whereby the housing 49 can be locked to nut 81 at selected positions for a purpose to be seen.

The sensor assembly 32 is assembled to the flow tube 16, as shown in FIGS. 1-3, with the housing 49 slidably supported in the boss 65. The counterbore 71 is internally threaded and threadably receives an externally threaded portion 85 on lock nut 81. As assembled the O-ring 73 is located in' counterbore 79 and is engageable with the shoulder 77 on locking collet 75; the sensor assembly 32 can be selectively, positionally located within the necked down portion 24 of flow tube 16 and can be locked in that position via the action of the lock nut 81'and collet 75; the nut has a plurality of flats to facilitate gripping with a wrench. Thus the degree of extension of the housing 49 within the flow tube 16 can be selectively adjustedrThe sensor assembly 32 includes a suitable photo-responsive member (in an assembly generally indicated by the numeral 87) and can be connected to suitable output indicating apparatus (not shown) whereby an indication of the turbidity of the fluid being analyzed can be obtained. The output indicating apparatus can be of construction well known in the art and hence a description thereof has been omitted for purposes of simplicity.

As noted the turbidimeter '10, having the light source and photo-sensitive member opposite each other operates on the absorption, effect. With conventional turbidimeters, the distance between the light transmission window, i.e., such as window 40, and the opposite (for absorption operation) light receiving window is fixed and hence the turbidimeter will be operable over a determinable range of turbidity; if, however, an application experienced a substantially higher or lower level of turbidity a meaningful range'of indications of turbidity could not be obtained since the quantity of light transmitted would be insufficient or excessive for the associated detector and its associated circuitry, etc. Thus,

for example, a turbidimeter constructed to monitor or detect turbidity in an application involving fly ash in an aqueous solution would not, without modification, be used in an application involving a caustic mud slurry.

With the apparatus of the present invention, as shown and described, the length of the light path, i.e., distance X between light transmission window 40 and light receiving window 55, can be selectively varied whereby a different range of operation can be obtained. Thus for solutions having higher concentrations of waste materials the sensor assembly 32 can be selectively moved to a determinable position shortening the light path distanceX and for solutions with lower concentrations it can be moved to a determinable position lengthening the distance X. Note that the distance between the photo-responsive member (in assembly 87) and window 55 will remain the same despite positional adjustments of the assembly 32 to vary the distance X.

It should be understood that the present invention is not limited to absorption type turbidimeters but can be used with turbidimeters or fluid analyzers having a different construction. Looking now to FIG. 5, a modified form of the invention is shown for use with a turbidime. ter operating on Tyndall Effect. In the description of the embodiment of FIG. 5, elements similar to like elements in the embodiment of FIGS. 1-4 have been given the same numeral designation with the addition of the letter postscript 0. Thus in FIG. 5, the turbidimeter a, the sensor assembly 32a is mounted to a boss 65a which is located in quadrature with a light source 300; hence, turbidimeter 10a will be operable to provide indications of turbidity in response to Tyndall Effect. The light source 30a, however, is also selectively movably mounted and hence is constructed similarly to the sensor assembly 320 and includes a tubular housing 92, similar to housings 49 and 490; the light source 30a also includes suitablesealing means (such as O-ring 73, 73a) and locking means (such as 8!, 81a and 75, 75a); the sealing and locking means are not shown for purposes of simplicity. Thus the light source 30a can be positionally selectively adjusted along withthc sensor assembly 32a to vary the effective light path. Thus the range of operation can be selectively varied by changing the combined distances Xa, Xb, which is a characterictis or indication of the effective light path. To maximize the output of turbidimeter 10a a second selectively movable sensor assembly 32b, identical to sensor assembly 32a, is mounted directly opposite to sensor assembly 32a and a second selectively movable light source 30b, identical to light source 30a, is mounted directly opposite to light source 30a. Thus with the apparatus of FIG. 5 the possible selectable ranges are maximized.

In the embodiment of FIG. 5, the maximum Tyndall Effect'would be realized by locating the light sources 30a and 30b and the sensor assemblies 32a and 32b with their outer most remote windows (such as window 55) just adjacent to the area B which is defined by the intersection of the beams from light sources 300 and 30b and the field of view of the sensor assemblies 32a, 32b. Hence the maximum output possible can be selected by the apparatus of FIG. 5.

In FIG. 5, position indicating apparatus 90, including calibration marks and indicating pointer, is provided whereby the relative distance Xa, associated with sensor assembly 32a, can be determined to assist in calibration as well as in the determination of turbidity ranges; similar indicating apparatus could be used on sensor assembly 32b and light sources 30a, 30b whereby total light path information could be obtained; indicating apparatus, such as apparatus 90, could be used as well with the device of FIGS. 1-4.

With apparatus constructed in accordance with the present invention the turbidimeter or flow analyzer could be selectively adjusted by the manufacturer and fixed in those positions necessary to meet specific customer requirements; thus the manufacturer would be required to manufacture only one type of device to cover a vast range of applications. Also in some applications, while the type of contaminant may be the same, day to day operations could result in a wide variation of concentrations of that type of contaminant; with the present invention, this could be accommodated by simply varying the operating range by selectively moving the sensor assembly 32.

While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the invention.

What is claimed is:

l. A fluid analyzer comprising a flow tube assembly, said tube assembly comprising an elongated flow tube, said flow tube being tubular in shape and having an inlet and an outlet portion integral with an intermediate portion, said flow tube having at least two windows lo cated at said intermediate portion, connecting means for connecting said flow tube in a flow line carrying a fluid to be monitored, light means associated with one of said windows for transmitting light through said one window into said flow tube, detector means associated with the other of said windows for receiving light through said other window from the light transmitted into said flow tube, said windows defining a light path having a determinable length, and adjustment means associated with at least one of said windows for selectively varying said determinable length whereby different ranges of turbidity can be selected, said adjustment means comprising a tubular housing, mounting means for mounting said at least one of said windows to said tubular housing, support means for supporting said tubular housing for movement into or out of said flow tube transversely to the axis of said flow tube for selectively varying said determinable length, said tubular housing defining a cross-section substantially less than that of said intermediate portion of said flow tube whereby substantial clearance for fluid flow remains around said tubular housing when it is located in the fluid path through said intermediate portion.

2. The fluid analyzer of claim 1 further including means for providing an indication of the magnitude of said determinable length.

3. The fluid analyzer of claim 1 with said adjustment means comprising lock means for locking said tubular housing in selected positions.

4. The fluid analyzer of claim 1 with said detector means comprising a photo-responsive member, means supporting said photo-responsive member to said tubular housing a fixed preselected distance from said at least one of said windows.

5. The fluid analyzer of claim 1 with said windows being located opposite from each other.

6. The fluid analyzer of claim 4 with said windows being located opposite from each other and further including means for providing an indication of said deter.- minable length.

7. The fluid analyzer of claim 1 with said windows being located in quadrature with each other.

8. The fluid analyzer of claim 6 with said windows ther including means for providing an indication of Said a through said other window from the light transmitted into said flow tube, said windows defining a light path having a determinable length, and adjustment means associated with at least one of said windows for selectively varying said determinable length whereby different ranges of turbidity can be selected, said adjustment means including first means associated with said one of said windows for selectively moving said one window into or out of said flow tube for varying said determinable length and second means associated with the other of said windows for selectively moving said other window into or out of said flow tube for varying said determinable length.

beam and field of view of said windows, said first and determinable length.

9. The fluid analyzer of claim I with said adjustment means associated with both of said windows for selectively varying said determinable length.

10. The fluid analyzer of claim 1 with said detector means comprising a photo-responsive member, means supporting said photo-responsive member to said tubular housing a fixed preselected distance from said at least one of said windows, and means supporting said light means at a fixed preselected distance from the other of said windows.

11. A fluid analyzer comprising a flow tube assembly, said tube assembly comprising a flow tube having at least two windows, light means associated with one of ,said windows for transmitting light through said one second means operable for moving the associated ones of said windows at least up to the perimeter of said pattern.

13. The fluid analyzer of claim 11 with said detector means comprising a photo-responsive member, means supporting said photo-responsive member to said tubular housing a fixed preselected distance from said at least one of said windows, and means supporting said light means at a fixed preselected distance from the other of said windows.

14. A fluid analyzer comprising a flow tube assembly, said tube assembly comprising a flow tube having at least three windows, light means associated with one of said windows for transmitting light through said one window into said flow tube, detector means associated with the others of said windows for receiving light through said other windows from the light transmitted into said flow tube, said one of said windows being opposite one of said other windows and in quadrature the other of said other windows, said one of said windows defining with said'other windows light paths having determinable lengths, and adjustment means associated with at least one of said windows for selectively varying said determinable lengths whereby different ranges of turbidity can be selected.

15. The fluid analyzer of claim 14 comprising a fourth window located in quadrature with said one of said windows, said adjustment means associated with said fourth window for selectively varying said determinable lengths between said one window and said fourth window.

UNITED STATES PATENT oTTItE Q'HFECATE F QUECHN Patent No. 3vglor695 Dated y 1974 Inventor(s) James J, Shea It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 350, delete "6" and substitute therefor -4-- igned and tis A Nest.

RUTH C. MASON C. MARSHALL DANN Arresting Officer ('ummissium'r nj'lan'nls and Trademarks 

1. A fluid analyzer comprising a flow tube assembly, said tube assembly comprising an elongated flow tube, said flow tube being tubular in shape and having an inlet and an outlet portion integral with an intermediate portion, said flow tube having at least two windows located at said intermediate portion, connecting means for connecting said flow tube in a flow line carrying a fluid to be monitored, light means associated with one of said windows for transmitting light through said one window into said flow tube, detector means associated with the other of said windows for receiving light through said other window from the light transmitted into said flow tube, said windows defining a light path having a determinable length, and adjustment means associated with at least one of said windows for selectively varying said determinable length whereby different ranges of turbidity can be selected, said adjustment means comprising a tubular housing, mounting means for mounting said at least one of said windows to said tubular housing, support means for supporting said tubular housing for movement into or out of said flow tube transversely to the axis of said flow tube for selectively varying said determinable length, said tubular housing defining a cross-section substantially less than that of said intermediate portion of said flow tube whereby substantial clearance for fluid flow remains around said tubular housing when it is located in the fluid path through said intermediate portion.
 2. The fluid analyzer of claim 1 further including means for providing an indication of the magnitude of said determinable length.
 3. The fluid analyzer of claim 1 with said adjustment means comprising lock means for locking said tubular housing in selected positions.
 4. The fluid analyzer of claim 1 with said detector means comprising a photo-responsive member, means supporting said photo-responsive member to said tubular housing a fixed preselected distance from said at least one of said windows.
 5. The fluid analyzer of claim 1 with said windows being located opposite from each other.
 6. The fluid analyzer of claim 4 with said windows being located opposite from each other and further including means for providing an indication of said determinable length.
 7. The fluid analyzer of claim 1 with said windows being located in quadrature with each other.
 8. The fluid analyzer of claim 6 with said windows being located in quadrature with each other, and further including means for providing aN indication of said determinable length.
 9. The fluid analyzer of claim 1 with said adjustment means associated with both of said windows for selectively varying said determinable length.
 10. The fluid analyzer of claim 1 with said detector means comprising a photo-responsive member, means supporting said photo-responsive member to said tubular housing a fixed preselected distance from said at least one of said windows, and means supporting said light means at a fixed preselected distance from the other of said windows.
 11. A fluid analyzer comprising a flow tube assembly, said tube assembly comprising a flow tube having at least two windows, light means associated with one of said windows for transmitting light through said one window into said flow tube, detector means associated with the other of said windows for receiving light through said other window from the light transmitted into said flow tube, said windows defining a light path having a determinable length, and adjustment means associated with at least one of said windows for selectively varying said determinable length whereby different ranges of turbidity can be selected, said adjustment means including first means associated with said one of said windows for selectively moving said one window into or out of said flow tube for varying said determinable length and second means associated with the other of said windows for selectively moving said other window into or out of said flow tube for varying said determinable length.
 12. The fluid analyzer of claim 11 with said one and other windows being in quadrature with each other and having a pattern defined by the intersection of the beam and field of view of said windows, said first and second means operable for moving the associated ones of said windows at least up to the perimeter of said pattern.
 13. The fluid analyzer of claim 11 with said detector means comprising a photo-responsive member, means supporting said photo-responsive member to said tubular housing a fixed preselected distance from said at least one of said windows, and means supporting said light means at a fixed preselected distance from the other of said windows.
 14. A fluid analyzer comprising a flow tube assembly, said tube assembly comprising a flow tube having at least three windows, light means associated with one of said windows for transmitting light through said one window into said flow tube, detector means associated with the others of said windows for receiving light through said other windows from the light transmitted into said flow tube, said one of said windows being opposite one of said other windows and in quadrature the other of said other windows, said one of said windows defining with said other windows light paths having determinable lengths, and adjustment means associated with at least one of said windows for selectively varying said determinable lengths whereby different ranges of turbidity can be selected.
 15. The fluid analyzer of claim 14 comprising a fourth window located in quadrature with said one of said windows, said adjustment means associated with said fourth window for selectively varying said determinable lengths between said one window and said fourth window. 